public class Main {

    //求和
    //求 1 ~ 20240408 中每个数的和

    public static void main1(String[] args) {
        long ans = 0;
        for (int i = 1; i <= 20230408 ; i++) {
            ans += i;
        }
        System.out.println(ans);
    }

    public static void main(String[] args) {
        System.out.println((long)20230408*20230409/2);
    }
}
